Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Se o nome do mercado for Xperia U, qual é o peso?
 ###Tabelas: CREATE TABLE national_team_matches (national_team_matches_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Location VARCHAR, Opponenent VARCHAR, Result VARCHAR, Match type VARCHAR) CREATE TABLE smartphones (smartphones_id AUTO_INCREMENT PRIMARY KEY, Code name VARCHAR, Market name VARCHAR, Platform VARCHAR, Release date VARCHAR, Android version VARCHAR, System on chip VARCHAR, RAM VARCHAR, ROM VARCHAR, Display VARCHAR, Weight VARCHAR, Battery ( mAh ) INT, Bluetooth VARCHAR, Wi-Fi VARCHAR, NFC VARCHAR, Camera VARCHAR, Network VARCHAR) CREATE TABLE regular_season_and_post-season_games (regular_season_and_post-season_games_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Kicker VARCHAR, Kicking team VARCHAR, Opponent VARCHAR, Yards INT, Result VARCHAR, Game time VARCHAR) CREATE TABLE group_b2 (group_b2_id AUTO_INCREMENT PRIMARY KEY, Nation VARCHAR, Skip VARCHAR, Third VARCHAR, Second VARCHAR, Lead VARCHAR) CREATE TABLE top_15_countries_by_tally (top_15_countries_by_tally_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Country VARCHAR, Miss Universe INT, 1st Runner-up INT, 2nd Runner-up INT, 3rd Runner-up INT, 4th Runner-up INT, Semifinalists INT, Total INT)  
SELECT Weight FROM smartphones WHERE Market name = Xperia U